This protocol is a multicenter collaborative trial of Home Infant Apnea Monitors. These devices are used to monitor breathing and heart rate in infants thought to be at risk for SIDS. This study will yield extensive descriptive information regarding the efficacy of apnea monitors, their accuracy, and the ability of these devices to detect clinically important events. The follow-up of the infants continues until approximately age 1.5 yrs. The GCRC Psychometrists assist with the developmental assessments.